Method of producing guns



Oct. 12, 1943. A. w. KEEMA 2,331,477

METHOD OF PRODUCING GUNS Filsd Sept. 18, 1942 INVENTOR xavza/ar W/L e ema ATTORNEYS Patented Oct. 12, 1943 um'rso STATES PATENT oFFlcE nlmrnon 1 :83am GUNS I. Q 1

6 Claims.

'I'his invention relates to a gun, more particularly to the bore of the gun.

It is usual in the finishing of the bore of a gun to rifle the bore so that a bullet will spin about its axis as it is projected from the gun.

The bullet is projected from the gun by the expansion of the explosive gases which drive the bullet forwardly. In order to increase the force of the bullet it is known that if the bullet is retarded just prior to the time it leaves the gun bore the gases through their expansion will develop a greater force and project the bullet at a greater speed than were such restrictions not provided. However, the known operations today do not proyide a means for restricting the rifle bore of a gun.

One of the objects of this invention is to provide a method by which a gun bore may be reduced in diameter at its outer end so as to provide a restriction to the passage of a bullet just prior to its leaving the muzzle of the gun.

Another object of this invention is to provide such restriction by compression of the gun bore from external forces along such portion as is desired should be reduced.

With these and other objects in view, the invention consists of certain novel features of construction, as will be more fully described and particularly pointed out in the appended claims.

In the accompanying drawing:

Fig. 1 is a longitudinal sectional view through a gun barrel which has been formed in accordance with this invention;

Fig. 2 is a fragmental elevation of a swaging machine illustrating in section the gun barrel as located between the dies of the machine;

Fig. 3 is an elevation of the gun barrel just after the swaging operation has been performed, the showing being exaggerated;

Fi 4 is an elevation after further treatment of the gun barrel to remove any swaging indications.

In proceeding with this invention the gun barrel is rifled in the usual manner and then after the rifling has been performed along the length of the uniform bore barrel, I compress the barrel alon the muzzle end portion such as in a swaging machine so as to restrict the mouth end of the bore and then by a. subsequent operation such as turning in a lathe I remove along the length of the gun barrel from the muzzle end rearwardly an amount so that the swaging operation is obscured.

With reference to the drawing HI designates generally the barrel of a gun which has been turned on its outer surface H to provide severai different diameters. Also the barrel is bored tc provide a larger diameter l2 and a smaller diameter [3 with a tapered connection portion M This diameter I3 extends from the tapered portion It outwardly to the muzzle end ii of the gun and is of a uniform diameter when first formec' throughout this length. Rifling as designated at [6 is provided along the length of the bore I3 01 uniform diameter and this rifiing is then lapped in a usual manner so as to finish the same.

After the rifiing in the uniform diameter bore has been provided the muzzle end portion of the gun is placed in a swaging machine designated generally at I l in Fig. 2. The barrel with its riiiing is designated II in section in this figure as placed between dies [8 and I9 which are subjected to striking by hammers such as 20 each of which is provided with a roll 2| to be contacted by the head rolls 22 which are rotatably mounted in the head ring 23 which is revolved about the axis of the barrel as a center so as to successively strike the hammer roll and drive the hammer inwardly to hit the dies which engage the gun barrel.

This hammer action occurs rapidly in fast succession and places the gun barrel under considerable momentary compression of such an amount as to reduce the barrel by compression along the outer surface and also along the bore portion of the barrel which is subjected to this action. The muzzle end portion is treated in such a way as to reduce the bore along the distance a substantially uniformly and to provide a tapered portion 17 (see Fig. 1) connecting this uniform projection portion a with a larger portion 0 which remains unchanged in diameter. This restriction will be only a few thousandths of an inch to provide the choke which is desired.

After the gun barrel has been so swaged its outer surface will have a reduced portion designated 25 (see Fig. 3) and tapered portion designated 26 and an unchanged portion designated 21. Then in order to provide a better finished surface and one of uniform appearance I have turned or ground down the barrel so as to provide a uniform outer surface 28 along these three dif ferent diameter portions as shown in Fig. 4. This latter operation also serves to conceal the means by which the muzzle portion is reduced which is highly advantageous during the time a nation is in war.

I claim:

. 1. The combination of steps in producing a gun which consists in rifiing the gun bore, and

compressing the barrel adjacent the discharge end to reduce the diameter of the rifled bore.

2. The combination of steps in producing a gun which consists in rifling the gun bore, compressing the barrel adjacent the discharge end by contact with the outer surface to reduce the diameter of the outer surface and the rifled bore and subsequently removing from said' outer surface any impression of such compressing.

I 3. The combination of steps in producing a gun which consists in. rifiing the gun bore, and swaging the outer surface of the barrel adjacent .\the discharge end to reduce the diameter of the:

4. The combination of steps in producing a discharge end to reduce the diameter of the outer surface and the rifled bore and subsequently moving from said outer surface any impression of such swaging.

5. The combination of steps in producing a, gun which consists in rifling the gun bore, swaging the outer surface of the barrel adjacent the discharge end to reduce the diameter of the rifled bore and provide a smaller bore at the discharge end connected to the larger bore by a tapering portion. r

6. The combination of steps in producing a gun which consists in rifiing the gun bore, and compressing the outer surface of the barrel ad- Jacent the discharge end for a short portion to 1'5 uniformly reduce the dameter of the rifled bore and to taperingly connect the reduced diameter to the larger size of the bore.

ALEXANDER W. 

